Good target afr for '14 coyote?

[WS6 GreeN]

Was helping a friend with his '14 Mustang and was wondering on these cars what WOT AFR should I be shooting for? He recently dynoed it and it was 11.7:1 at WOT across the board. When looking at the tune, stoich is set to 14.0 and WOT commanded lambda works out to that AFR. Thanks in advance!

[wbt]

Was helping a friend with his '14 Mustang and was wondering on these cars what WOT AFR should I be shooting for? He recently dynoed it and it was 11.7:1 at WOT across the board. When looking at the tune, stoich is set to 14.0 and WOT commanded lambda works out to that AFR. Thanks in advance!

Stock AFR is set to 14.08. .83 lambda tends to work pretty well for N/A stuff on 91/93 octane. Looks like he is right in that zone.

[MMGT1]

How is 11.7 ok on a NA motor? Is this boosted? I thought an NA engines limit was around 12.5 or so. The Ford stuff is very new to me...

[WS6 GreeN]

How is 11.7 ok on a NA motor? Is this boosted? I thought an NA engines limit was around 12.5 or so. The Ford stuff is very new to me...

I was thinking the same thing. What is crazy is the stock AFR calculates to lower than that. No, the car is not boosted and only has CAI, exhaust and no cats.

[MMGT1]

Be great to get Eric's input or some of the experienced Ford guys to clear this up. I have seen where we CANNOT treat this plant like a GM. There is no 13.0 and 28* of timing with these, she wil go boom I'm told! So I am working with their goals to stay safe for now

[wbt]

Comes down to combustion chamber design and compression ratio.

These engines like a bit more fuel and ~25* of timing for N/A applications on 93. That is where they make best power.

For FI .78 to .80 lambda is typically used with ~15* of timing with 93.

[toyoguru]

wbt pretty much summed it up with where these cars are good a/f wise. Also, cam timing can net some good gains too.

[WS6 GreeN]

Comes down to combustion chamber design and compression ratio.

These engines like a bit more fuel and ~25* of timing for N/A applications on 93. That is where they make best power.

For FI .78 to .80 lambda is typically used with ~15* of timing with 93.

So how much fuel is a bit more fuel for NA?

[toyoguru]

My personal experience is 11.6-11.7, depending on ignition/cam timing.

Also, remember, this is all based off of a lambda, .83 being a good starting point, referenced off of a stoich AFR of 14.08, which is basically E10. Take that same lambda of .83 and reference from the older stoich 14.68-14.7 and you end up in the 12.1-12.2 range.

Its a lot better to err on the side of rich with the coyote..as mine runs pretty strong even with an 11.2 afr, which is where my WOT lambda is for nitrous, and I run that tune all the time.

[Freakotec]

Wow. I'm pretty amazed at how rich these things run. Is there anything behind this other than "that's what it should be", and combustion chamber size? It just seems to go against anything you've ever known for tuning a N/A engine. Has anyone tested say .80lambda vs .90lambda, or maybe have any theory behind this?

[toyoguru]

I haven't put either of my cars on a dyno, but my 13 GT lost 2 mph consistently going from .835 lambda to .845 lambda..same day same conditions, three runs on both tunes (6 runs total) with the only change being the lambda in the tune. The mph stayed the same .825 to .835..so I kept it at .835 NA. It really threw me off too when I first starting tuning them.

[wbt]

Wow. I'm pretty amazed at how rich these things run. Is there anything behind this other than "that's what it should be", and combustion chamber size? It just seems to go against anything you've ever known for tuning a N/A engine. Has anyone tested say .80lambda vs .90lambda, or maybe have any theory behind this?

I am sure it would take a Ford engineer who worked on the head design to provide the details on the why.

Looking at the basics we know that an engine likes more fuel when it is moving more air. My answer to the question is, more efficient head design.

[SultanHassanMasTuning]

Best power I have found is .835 stock headers, and .85 with after market headers

[Eric@HPTuners]

Don't forget the higher cranking compression of these engines vs the earlier 4Vs. I'm sure on a good high octane fuel you would make more power being leaner, but on pump gas, you can run slightly more timing without running into detonation with a richer mixture.

[wbt]

Don't forget the higher cranking compression of these engines vs the earlier 4Vs. I'm sure on a good high octane fuel you would make more power being leaner, but on pump gas, you can run slightly more timing without running into detonation with a richer mixture.

+1. I have calmed knock down with some cars by adding a little more fuel in certain spots.

[MMGT1]

With these, are you guys changing Stoich to match actual? Testing fuel for E content and inputting correct data?

[wbt]

With these, are you guys changing Stoich to match actual? Testing fuel for E content and inputting correct data?

Not here. Just leave it at the stock 14.08 setting for regular gas and 9.85 for e85.

[NewJack]

for some reason i cant find where to change my stoich. Anyone know where that might be i am looking to swap to e85 but just upgraded my beta and cant find it.

thanks

[MMGT1]

Should be the first thing you see in the Fuel Tab: General: Stoich AFR, it'll be set to 14.08000 stock

[NewJack]

I thought it was there also but it seems that i just installed the newest beta and its not there . really weird